Spectral expansion analysis in electrical impedance tomography

The EIT image domain is expanded in a complete set of orthogonal basis images. The number of basis images is given by the number of independent measurements (104 for 16 electrodes). They are ordered according to their sensitivity to data noise, with centrally located features and higher spatial frequency components appearing towards the higher terms in the series. This indicates that the resolution can be improved at the expense of degrading signal to noise in the reconstructed image. The technique offers a flexible way of assembling a reconstruction protocol. A specific reconstruction algorithm similar to the algebraic reconstruction technique (ART) is analysed to show its regularization properties.